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Sandco provided only two pre-mining longitudinal profiles, for 1996 and 2002. As of November 14, Hermosa Meadows Gravel has not yet provided a longitudinal profile for 2003. 5.4 Compliance with Mining Requirements • I have not compared baseline thalweg elevations to annual excavation depths because the lack of tabular numeric data would require extensive interpolation from graphs. However, the amount of thalweg incision since 1996 (see below) and the same operator for most of this period (Sandco) suggest that compliance may be compazable to that at the Dalton Pit (see Section 4.4). 5.5 Changes in River Channel (Primarily from Mining) • Since December, 1996, the thalweg has incised 3.1 ft on average (the most at any pit); large variability is reflected by incision ranging from 5.7 ft at section SC-1 to 1.5 ft at HM-1 (Table 7 and Figure 4). • Sequential examination of survey graphs for individual cross sections shows that thalweg incision was caused at least partly by mining below the 1996 thalweg level; the thalweg typically relocated to areas that had been mined below the previous yeaz's thalweg. • Since 1977, available data suggest incision of approximately 9-13 ft; incision is generally within the lower end of this range in the upstream part of pit and within the higher end of this range in the downsteam part of the pit (Table 7 and Figure 4). Accuracy of the 1977 data is uncertain, but changes of this magnitude are consistent with the relatively large height of the floodplain above the present channel. • Aerial photographs show long-term planform changes such as decreased sinuosity and reduction in number of secondary channels. 5.6 Suggested Modifications Same as for Dalton, with following additions: Data from the cross section at the boundary with the Dalton Pit (SC-1) is essential to meet the spacing requirements for this pit. Hermosa Meadows Gravel needs to track and report changes at its downstream boundary, so it must either establish its own cross section there, or obtain future survey data for SC-1 from Sandco and include it in the Hermosa Meadows reports to USACE. Hermosa Meadows Gravel should obtain previous tabular numeric survey data from Sandco for existing sections within the Hermosa Meadows Pit, and should provide that data to USACE. The request by Hermosa Meadows Gravel to mine an older inactive channel in the northeast part of its permit area should be carefully evaluated and possibly denied. According to Kara Hellige, Hermosa Meadows Gravel wants to mine this channel to split the river's flow and thus decrease erosion along the west bank of the existing channel, near a home that lies a short distance upstream from the pit's northern boundary. Gillam to Hellige, Nov. 28, 2003 page 12